Printing machine belt assembly

ABSTRACT

A printing machine belt assembly including a unitary clip having hooks integrally joined to an elongated backplate and coextensive therewith to form a pair of locking channels opening toward one another for receiving free ends of a printing belt. The belt is conveniently spliced by inserting preformed end folds of the printing belt in the channels and then sliding the clip across the width of the printing belt to join its free ends.

United States Patent [72] Inventor Edward A. Stroud Wharton, NJ. [21] Appl. No. 746,948 [22] Filed July 23, 1968 [45] Patented July 6,1971 [73] Assignee Cameron Machine Company Dover, NJ.

I 54] PRINTING MACHINE BELT ASSEMBLY 5 Claims, 3 Drawing Figs.

[52] U.S.C1 10l/4l5.l, 198/193, 24/35 {51] Int. Cl 841i 27/06 [50] FieldofSearch 101/141, 178, 415.1, 223; 24/31, 35, 38; 198/193 [56] References Cited UNITED STATES PATENTS 769,296 9/1904 Bender 101/141 1,033,774 7/1912 Andres et al 24/31 2,128,343 8/1938 Bemisetal. 101/178 2,176,595 10/1939 Pannier... 101/415.1 2,324,171 7/1943 Paradise 24/31 X 2,930,318 3/1960 Stroud 101/223 3,430,561 3/1969 Simmons 101/415.1

Primary Examiner-Robert E; Pulfrey Assistant Examiner-Alan E. Kopecki Att0rr|eyPrutZman, Hayes, Kalb & Ch-elton ABSTRACT: A printing machine belt assembly including a unitary clip having hooks integrally joined to an elongated backplate and coextensive therewith to form a pair of locking channels opening toward one another for-receiving free ends ofa printing belt. The belt is conveniently spliced by inserting preformed end folds of the printing belt in the channels and then sliding the clip across the width of the printing belt to join its free ends.

PATENTED JUL 6 I971 SHEET 1 BF 2 INVENTOR EDWARD A. STROUD BY ATTORNEYS PRINTING MACHINE BELT ASSEMBLY This invention relates to printing machines and particularly concerns an easily manipulated unitary clip for splicing two end portions of the same printing belt.

A primary object of this invention is to provide an improved printing machine belt assembly incorporating a clip which is quick and easy to use in securing free ends of a printing belt and which is readily detachable when it is desired to disassembly the belt.

Another object of this invention is to provide an improved clip for splicing a printing belt of a type having a series of sprocket holes extending along a side edge of the belt. lncluded in this object is the provision of a unique clip which is so dimensioned that, upon tensioning the spliced belt, its sprocket holes will automatically be positioned to register with a sprocket wheel for driving the belt.

A further object of this invention is to provide an improved clip of the above described type which is manufactured at low cost and is durable to give long reliable service under rugged operating conditions.

Still another object of this invention is to provide an improved clip which is particularly suited to ensure against its smudging a web being printed.

Other objects will be in part obvious and in part pointed out more in detail hereinafter.

The invention accordingly consists in the features of construction, combination of elements and arrangement of parts which will be exemplified in the construction hereafter set I forth and the scope of the application which will be indicated in the appended claims.

In the drawings:

FIG. 1 is a perspective view, partly broken away and partly in section, showing a printing belt assembly incorporating this invention supported on a plate cylinder of a printing machine;

FIG. 2 is a partial bottom view, partly broken away, showing .a clip of this invention attached to a printing belt; and

FIG. 3 is an enlarged section view, partly broken away and partly in section, taken generally along line 3-3 of FIG. 2 showing the clip joining free ends of the belt which is in aligned but exploded relation to sprockets shown in broken lines.

Referring to the drawings in detail, FIG. 1 illustrates a part of a printing machine 10. The latter includes a plate cylinder 12 which will be understood to be rotatably supported on a frame, not shown, and which is positioned below an impression cylinder 14 around which a paper web 16 passes to engage a plurality of flexible printing plates 18, shown fixed to a printing belt 20, after the plates 18 have been inked by an inker 22. In addition to the plate cylinder 12, additional rotary supports such as spaced parallel idler rolls, not shown, will be understood to be provided to support the printing belt 20 for continuous movement along a path in one direction past the inker 22 prior to engaging the web 16 traveling over the impression cylinder 14.

The printing plates 18 are suitably bonded to the belt 20 which is preferably formed of a polyethylene terephthalate or Mylar" sheet or other commercially available tough, selfsupporting, flexible solid sheet material. Such material should exhibit high tensile and tear strength over a wide range of temperatures and humidities, in addition to good elongation and high impact resistance, to provide a dimensionally stable and rugged belt for use in a printing mechanism.

The belt 20 is shown punched along a side edge to provide a row of holes 24 for registering with a series of circumferentially spaced sprockets 26 formed on a sprocket wheel 28. While it will be understood that two sprocket wheels can be provided, for purposes of illustration only the one sprocket wheel 28 is shown coaxially mounted at the end of the plate cylinder l2.

To provide quick and easy attachment of the free ends of the belt 20 as well as to permit convenient disassembly, a one piece clip 30 provided in accordance with this invention securely joins the printing belt 20 in an efficient, simplified manner free of the normal difficulties associated with conventional belt connecting devices. In the specific illustrated embodiment, the clip 30 is formed of a thin strip of rugged material such as stainless steel and the like having a uniform thickness to provide an elongated generally rectangular flat blank which is then shaped and bent to form.

So that only an inner surface 32 of the belt 20 will be presented to the peripheral surface 34 of the plate cylinder 12 to ensure precision printing of the web 16, the clip 30 is fon'ned to provide a generally C-shaped cross section having an exposed elongated back plate 36 from opposite side edges 38, 40 of which extend a pair of reversibly curved hooks 42, 44 coextensive with the longitudinal side edges 38, 40 of the back plate 36. The hooks 42, 44 are arranged to project toward one another and provide a pair of aligned, longitudinally extending belt-locking channels 46, 48 which receive end folds 50, 52 of the belt 20, each of which is bent over upon itself and located in captured relation between the hooks 42, 44 and the back plate 36 as seen in FIG. 3.

By virtue of this structure, no portion of the clip 30 can possibly contact the plate cylinder 12 to cause, e.g., any portion of the belt 20 passing over it to be undesirably raised out of engagement with the peripheral surface 34 of the plate cylinder 12 during printing of the web 16.

The hooks 42, 44 of the clip 30 have a lower belt-engaging surface 54 and an opposite concealed inner surface such as at 56 facing the backplate 36. The inner surface 56 of each hook 42, 44 is spaced from the backplate 36 a predetermined distance somewhat greater than the thickness of the belt 20 but preferably less than the thickness of the clip 30. To ensure that the end folds 50, 52 of a slack belt 20 will be temporarily secured while also ensuring that the overall height of the sandwiched layers of belt and clip portions will be substantially less than the height of raised impression surfaces 58 of the printing plates 18, it has been found that a clip 30 having a thickness of about 19 mils and locking channels of approximately 15 mils, e.g., is suitable for a belt of approximately 10 mils thickness having printing plates of, say, about 92 mils thickness.

The hooks 42, 44 are also of a predetermined size with a major cross-sectional dimension greater than one-third but less than one-half that of the backplate 36. To further ensure against any possibility of an inked clip 30 smudging the web 16, the backplate 36 has an arcuate cross sec-tion with a curvature conforming to that of the plate cylinder 12, as seen in FIG. 3, it being understood that the spliced belt in this figure is shown in exploded relation to the plate cylinder 12 only for purposes of clarity of illustration. Such construction provides facile assembly and disassembly with a minimum of effort while at the same time providing an extremely tenacious grip on the belt 20 along longitudinally extending terminal edges or gripping edges 60, 62 of the books 42, 44.

Preferably, the free ends of the belt 20 are prefolded to form the end folds 50, 52. After the end folds 50, 52 have taken a set, a leading end of the clip 30, such as the left-hand end of the clip viewed in FIG. 2, is aligned with the end folds 50, 52 such that upon sliding the clip 30 to the left the belt 20 will be temporarily but securely joined. A series of such clips 30 are shown installed in end-to-end abutment across the width of the belt 20 with only its marginal edges being unsupported by a clip 30 to ensure against any possibility of interference with the sprockets 26. Holes may be formed, such as at 64, to provide convenient tool-engaging portions such that a hooked wire or the like may be used to assist sliding the clips 30 onto the belt 20.

To automatically position the sprocket holes 24 along the edges of the spliced printing belt 20 in registration with the sprockets 26, the opposed gripping edges 60, 62 of the hooks 42, 44 are uniformly spaced apart a distance corresponding to the minimum dimension separating adjacent sprocket holes 24 formed in the belt 20. Assembly is considerably facilitated by such controlled dimensional relation of the gripping edges 60, 62 of the clip 30 since the end folds 50, 52 of the belt 20 may then be bent over laterally along a line tangent to the edge of a sprocket hole hear the free end of the belt, such as at 24a, whereby upon tensioning the spliced belt 20, the sprocket holes on each side of the clip 30 will be positioned to register with the sprockets 26.

A printing belt clip formed in accordance with the abovedescribed invention will be seen to provide a relatively lightweight, easily assembled and disassembled means for joining the free ends of a printing belt. The tension in the belt serves both to press the clip toward the plate cylinder, whereby only the inner surface of the printing belt comes into contact with the surface of the'plate cylinder for enabling precision printing, while also preventing the belt ends from slipping out of interlocked engagement within the channels of the clip. An exceptionally stable grip has been found to be effected on the ends of the belt for trouble-free operation under running tension even at operating speeds as highas 1,000 feet per minute.

As will be apparent to persons skilled in the art, various modifications and adaptations of the structure above described will become readily apparent without departure from the spirit and scope of the invention, the scope of which is defined in the appended claims.

I claim:

1. in a printing machine of a type including an impression cylinder, web-feeding means for passing a web to be printed over the impression cylinder, and a plurality of printing belt rotary supports including a plate cylinder positioned in adjacent parallel relation to the impression cylinder, a printing belt assembly comprising printing belt means having an outer surface with flexible printing plates fixed thereto and an inner surface engageable with the rotary supports, the printing belt means being of perforated construction having a row of holes formed adjacent a side edge thereof, a driven sprocket wheel registrable with the holes of the belt means to drive the same, and a one-piece clip detachably connecting free ends of the printing belt means, the clip being formed of a rigid strip of generally C-shaped cross section having an elongated backplate with longitudinal side edges and a pair of reversely turned hooks integral therewith and projecting toward one another, the hooks providing a pair of longitudinally extending belt-gripping edges uniformly spaced apart a distance corresponding to a minimum distance between the adjacent holes formed in the belt means, the printing belt meanshaving free ends respectively folded over the hooks to extend in opposite directions in captured relation between the hooks and the backplate of the clip whereby, upon being tensioned, the belt means is firmly secured in engagement with the gripping edges of the clip with only the inner surface of the belt means engaging the plate cylinder and the holes on each side of the clip automatically being positioned to register with sprockets of the sprocket wheel.

2. The printing belt assembly of claim 1 wherein the backplate has an arcuate cross section with a curvature substantially conforming to that of the peripheral surface of the plate cylinder.

3. The printing belt assembly of claim 1 wherein the backplate of the clip is exposed and positioned substantially below the surface of the printing plates to ensure against any smudging of the web to be printed.

4. The printing belt assembly of claim 1 further including an additional clip aligned in end-to-end abutment with said one clip across the belt means and joining its free ends, the clips having at least one exposed end disposed inwardly of the holes in the belt means in noninterfering relation with the sprocket v wheel.

5. In a printing machine, a printing belt assembly comprising printing belt means having a row of holes formed adjacent a side edge thereof, rotary supports supporting the printing belt means, a driven sprocket wheel having sprockets thereon registrable with the holes of the belt means for driving the same, and an elongated clip of generally C-shaped cross section including longitudinally extending belt-gripping edges uniformly spaced apart from one another a distance corresponding to the minimum distance between adjacent holes in the belt means and forming a pair of locking channels for respectively receiving a free end of the belt means. 

1. In a printing machine of a type including an impression cylinder, web-feeding means for passing a web to be printed over the impression cylinder, and a plurality of printing belt rotary supports including a plate cylinder positioned in adjacent parallel relation to the impression cylinder, a printing belt assembly comprising printing belt means having an outer surface with flexible printing plates fixed thereto and an inner surface engageable with the rotary supports, the printing belt means being of perforated construction having a row of holes formed adjacent a side edge thereof, a driven sprocket wheel registrable with the holes of the belt means to drive the same, and a onepiece clip detachably connecting free ends of the printing belt means, the clip being formed of a rigid strip of generally Cshaped cross section having an elongated backplate with longitudinal side edges and a pair of reversely turned hooks integral therewith and projecting toward one another, the hooks providing a pair of longitudinally extending belt-gripping edges uniformly spaced apart a distance corresponding to a minimum distance between the adjacent holes formed in the belt means, the printing belt means having free ends respecTively folded over the hooks to extend in opposite directions in captured relation between the hooks and the backplate of the clip whereby, upon being tensioned, the belt means is firmly secured in engagement with the gripping edges of the clip with only the inner surface of the belt means engaging the plate cylinder and the holes on each side of the clip automatically being positioned to register with sprockets of the sprocket wheel.
 2. The printing belt assembly of claim 1 wherein the backplate has an arcuate cross section with a curvature substantially conforming to that of the peripheral surface of the plate cylinder.
 3. The printing belt assembly of claim 1 wherein the backplate of the clip is exposed and positioned substantially below the surface of the printing plates to ensure against any smudging of the web to be printed.
 4. The printing belt assembly of claim 1 further including an additional clip aligned in end-to-end abutment with said one clip across the belt means and joining its free ends, the clips having at least one exposed end disposed inwardly of the holes in the belt means in noninterfering relation with the sprocket wheel.
 5. In a printing machine, a printing belt assembly comprising printing belt means having a row of holes formed adjacent a side edge thereof, rotary supports supporting the printing belt means, a driven sprocket wheel having sprockets thereon registrable with the holes of the belt means for driving the same, and an elongated clip of generally C-shaped cross section including longitudinally extending belt-gripping edges uniformly spaced apart from one another a distance corresponding to the minimum distance between adjacent holes in the belt means and forming a pair of locking channels for respectively receiving a free end of the belt means. 